Vacuum feed mechanism



C. BHADBURY.

VACUUM FEED MECHANISM. v APPLICATION FILED ocr. 24. 1919. 1,346,482, Patented July 13, 192()-g s'sIIEETs sHEU I.

- ZUSTP Ward fzzabw/ C. C. BRADBURY.

VACUUM FEED MECHANISM.

APPLICATION FILED ocT'. 24, 1919.

1,346,482. 'Patented July 13, 1920.

-3 SHEETS-SHEET 2.

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C. C. BRADBURY.

VACUUM FEED MECHANiISM. APPLICATION FILED ocr. 24, |919.

1,346,482. Patented July 13, 1920.

3 SHEETS-SHEET 3.

PATENT OFFICE.

CLIFFORD C. BRADBURY, OF OAK PARK, ILLINOIS.

VACUUM FEED MECHANISM.

Application filed October 24, 1919.

To all whom t may concern:

Be it known that l, CLIFFORD C. BRAD- nUiiY, a citizen of the United States, residing at Oak Park, in the county of Cook and State of Illinois, have invented a certain new and useful Improvement iii Vacuum Feed Mechanism, of which the following is a full, clear, concise, and exact description, reference being had to the accompanying drawings, forming a part of this specification.

My invention relates to improvements in vacuum feed tanks of the type employed for lifting fuel from a main fuel tank located at a lower level, and fon supplying the fuel thus raised to a carbureter located .above the main tank and under the vacuum feed tank.

The suction utilized in the vacuum tank for lifting the fuel from the main 4tank is usually developed kin the intake manifold of the internal combustion engine with which the carbureter is associated, but in so far as my invention is concerned, any source of suction may be employed.

Tanks of this general type usually include a suction chamber having a suction port communicating therewith, a fuel inlet for supplying fuel to the suction chamber, a float operated in accordance with the fuel level in the chamber and a snap action valve device between the float and suction port for controlling communication between the suction port and the vacuum chamber. In most of the vacuum tanks now employed the snap action device controls an air inlet portl as well as they suction port, the ports y being alternately opened and closed by the snap action.

My invention is especially concerned with the snap action device interposed between the float and suction port or inlet port, vor both. The common form of snap action for vacuum tanks comprises one or more levers arranged to assume either one of two positions on opposite sides of a dead center line, together with means, usually spring means, for snapping the lever or levers away from the dead center line to oneof the said positions, the operation ofthe snap action occurring after the lever has been moved a slight distance beyond the dead center line. This common form ofl snap action is subject to a very serious objection, in that, its operation is such as to result in a sluggish action of the valve mechanism which it Specification of Letters Patent.

Patented July 13, 1920.

serial No. 332,908.

opeiates and controls. In order that the valve mechanism operate properly, it is necessary that some means be employed for holding the valve in its fully closed position until the snap action spring has been operated to remove the valve quickly awayV from its seat. In the common form of snap action above .referred to, the stress or spring tension tending to hold the valve closed is decreased as the snap action is moved toward the dead center line and becomes practically nothing when the snap action assumes the dead center line position, with the result that the valve is not pressed firmly against its seat until the snap action takes place.

Itis the primary object of the present invention 4to provide a snap action wherein a substantially constant stress is applied to the valve during the entire movement of the snap action toward and slightly beyond the dead center line. In the preferred forni of the invention, this object is accomplished b y providing two inter-connected snap actions, one of which is dependent for its operation on the second and which remains fixed until the operation of the first takes place. These and other objects of the present invention will be pointed out in detail in connection with the accompanying drawings, whercin- Y Figure l is a vertical cross-sectional view of a vacuum feed tank showing the improved mechanism of my invention;

Fig. 2 is an enlarged bottoni view of the snap action mechanism shown in Fig. l;

Fig. 3 is a vertical cross-sectional view taken along the line of Fig. 2 looking inthe direction indicated by the arrows;

Fig. 1l: is an enlarged vertical cross-sectional view takeii along the line 4--4- of Fig. l looking in the direction indicated by the arrows; n

Fig. 5 is a view similar to Fig. 3 showing a modified arrangement, and

Fig. G is a view similar to Fig. 5 showing bers l0 and 11. 'Extending through the plate l2 and affording con'nnunication between the chambers 1G and 11, is a pipe 13, the lower end of which is provided with a valve seat 14, adapted for cooperation with the valve 15 mounted on a up 1G, supported from the pipe 13. rfhe operation of the valve 15 is such as to prevent communication between the chambers 10 and 11 when suction is applied to the chamber 10. The lower end of the chamber 11 is provided with a fuel outlet 17, arranged for connection with a carbureter for supplying fuel to the latter.

Extending across the upper end of the casing 7, and disposed within the vacuum chamber 10, is a plate 18 forming an air-tight connection with the wall of the casing 7 at 19. Plate 1S is provided with a fuel intake port 20 arranged for connection with a conduit leading to the main fuel supply tank located at a lower level than the vacuum feed tank shown in this figure.

Extending upwardly through the top of the section 7 and forming part of the plate 13, is a double acting valve 21, the upper end of which, as shown at 22, is adapted for connection with a source of suction such as, for example, the intake manifold of the internal combustion engine with which the carbureter, above referred to, is associated. The detail construction of the valve mechanism 21 is most clearly shown in Fig. 4 and comprises a valve member 23 adapted for coperation with either one of the valve seats shown at 24 and 25. The valve seat 24 forms part of a conduit 25 communicating with the chamber 2G, interposed between the plate 13 and the top of the casing 7. This chamber has communication with atmosphere through the port 27. The valve 23 is provided with an annular groove, as most clearly shown in Fig. 4, into which extends the bifurcated end of the valve operating member 28, the valve operating member being controlled and operated by the snap action hereinafter referred to. From the description thus far given, it will be observed that when the valve 23 assumes the position shown in Figs. 1 and 4, communication is established between the suction port 22 and the vacuum chambei 1() and that when the valve 23 assumes its uppermost position in engagement with the seat 25, communication is established between atmosphere and the vacuum chamber.

Extending downwardly from plate 18 are two brackets or supports 28-23, to which is pivoted at 29-29 a U-shaped lever 30. T he free end of the lever 30 is pivotally connected at 31 to a float 32 carrying a guiding rod 33. extending into the pipe 13. Pivoted to the lever 30 at 34 is a second lever 35, the free end of which is pivotally connected at 3G with a third lever 37 connected at its outer end with the valve operating member 28.

The lever 37 extends into a notch 38 provided in the stop member 39 extending downwardly from the plate 1S. The upper and lower walls of the notch 38 serve as stops for limiting the movement of levers and 37 in the operation of the snap action Vas will be pointed out more clearly hereinafter. The outer end of the lever 37 is connected with two coiled springs 39 and 40 attached to the ci sing at 41. The tendency of the spring members 39 and 40 is to collapse the levers 35 and 37 or to move the lever 37 in a clockwise direction when the snap action assumes the position shown in Figs. land 3.

The operation of the device is as follows: Assuming that the suction port 22 is connected with some source of suction and that the several parts assume the position shown in Figs. 1, 2 and 3, suction is communicated to the vacuum chamber 10. The valve 23 is securely held against the lower seat 24 through the action of the springs 39 and 40. lV hen the snap action is in the position shown in Fig. 3, the springs 39 and 40 have a tendency to move the interconnected ends of the levers 35 and 37 upwardly. Such upward movement is, however', prevented by the stop 42, with the result that the springs 3S) and 40 have a tendency to swing the lever 37 in a clockwise direction, as shown in Fig. 3. As a result, the valve 23 is securely held againstthe seat 24. As suction is applied to the vacuum chamber 10, fuel is lifted from the main fuel tank and is passed into the vacuum chamber through the fuel duct 20. As the fuel enters the vacuum tank, the float 32 is moved. upwardly and the lever 30, which is connected with and operated by the float, is swung upwardly in a clockwise direction (Fig. The upward movement of the l'loat and lever 30 continues until the pivoted'point 34 reaches a point slightly above the dead center line, shown at 44 in Fig. 3. When the pivoted point 34 reaches this position, the inter-connected ends of levers and 37 are rapidly snapped downwardly to a position where the lever 37 engages the stop 43, whereupon the springs 39 and 40 swing the lever 37 in a counter-clockwise direction, and produce tight engagement between the valve member 23 and the valve seat 25. Vhen this takes place, communication between the suction port and the vacuum chamber is discontinued, and the vacuum chamber is subjected to atmospheric pressure. The fuel in the vacuum chamber is then permitted to flow downwardly through the pipe 13 into thesupply chamber 11 and thence to thel carbureter, the supply chamber being continually subjected to atmospheric pressure through the conduit 45 which af fords communication between the supply chamber and the air chamber 26. Attention is directed to the fact that the spring tension or stress applied to the valve operating mem- The operation of the snap action during the reverse movement of the lever 30 in a downward direction is identical with that above referred to. In the downward movement of the float, the pivot point 34 is moved downwardly beyond the dead center line, passing through the points 36 and 46, whereupon the springs 39 and 40 act to move the inter-connected ends of levers 35 and 37 upwardly against the stop 42 and to swing the lever 37 in a clockwise direction again seating the valve 23 against the seat 24. It will be observed from the above that there are two distinctsnap actions, one formed with the pivot points 34 and 46 acting as stationary points and the point 36 as the movable point and the second action with the point 36 as the stationary point and the point 46 as the movable. The second action, namely, that formed by the stationary point 36, the lever p 37 and the movable point 46, is dependent for its operation on the first action and its operation occurs immediately after the operation of the first action.

In the modifiedv arrangement shown in F ig. 5, the valve member 23 is arranged for coperation with the seats 24 and 25, cornmunicating respectivelyy with atmosphere and the suction producing n means. The lower end of the valve operating member 28 is pivotally connected with the lever 37, which has its inner end pivotally connected at 36 with a second lever 35. The levers 35 and 30 are pivotally connected to a fixed member at 47, the outer end of the lever being connected with the float as shown. Connecting the outer end of the lever 37 and the fixed pivot 47 is a spring 48, tending to collapse the levers and 37. A similar but stronger spring 49 is connected between the outer ends ot levers 3U and 35,

and tends to collapse the said levers. The inter-comiected ends of levers 35 and 37 are adapted for engagement with the stops 42 and 43". When thesnap action is in the position shown in this figure, the tendency of the spring 48 is to move the pivot point 36 upwardly and to move the valve operating member 28 downwardly, with the result that the valve member 23 is securely locked against the seat 25, When the parts are in the position shown in this figure, the vacuum ychamber has its full supply of fuel and is subjected to atmospheric pressure through the duct, of which the seat 24 forms a part. As the fuel in the vacuum chamber is permitted to pass downwardly into the supply chamber, the float is lowered until the point 50 is moved slightly beyond the dead center line shown at 44, The spring 49 then acts to move the pivot point 36 between the levers 35 and 37 ra idly downwardly against the stop 43a. hen this takes place, the spring 48 acts on the lever 37 and with the point 36 as a pivot, swings the lever 37 upwardly moving the valve 23a against the seat 24 and away from the seat 25. In this modification, one of the snap actions is formed by the levers 30 and 35 and spring 49, with the point 47 as the pivot. The second snap action is formed by the lever 37 and spring 48, with the point 36 as the pivot.

` Fig. 6 shows a further modification, in which a single spring is employed for operating both of the snap actions. In this arrangement, the fixed pivot is located at 51 and serves to pivot the lever 52 pivotally connected with the valve operating member 28b and the second lever 53. The other end of the lever 53 is pivotally connected at 54 with the third leverl 55 attached to and operated by the float. The inter-connected ends of levers 53 and 55 are disposed between the stops, similar in all respects to the stops shown in Fig. 5. In the operation of this modification, the float is moved downwardly until the point 56 is moved slightly beyond the dead center line 44, whereupon the single spring 57, acting between the points 5l and 56, quickly moves the point 54 upwardly against the stop and beyond the dead center line 44, passing 100 through the points 51 and 58. The movement of the point 54 beyond the dead center line 44c results in a quick downward .movement of the point 58, with the result that the valve is quickly moved from its upper seat and pressed firmly against its lower seat. Attention is again directed to the fact that the spring tension or stress applied to the valve tending to hold it against its seat, remains constant throughout the entire movement of the float mechanism, and that` there is no tendency to unseat the valve or to relieve pressure from the valve until the oat mechanism assumes a position where the snap action operates to unseat the valve.

The term snap action used throughout the specification and claims, is intended to cover all actions or mechanisms in which a lever or spring member is moved toward a dead center line and then quickly moved beyond the dead center line.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent of the United States is:

1. A snap action device for fuel feed tanks, comprising a plurality of inter-connected levers forming two snap actions, spring means for operating said actions, the operation of one of said actions being dependent upon the operation of the other of said actions, and occurring immediately after the operation of said other action.

y 2. A snap action device for fuel feed tanks, comprising a plurality of levers forming two snap actions, spring means for operating said actions, said actions being inter-connected whereby one of said actions is controlled by the other of said actions, and means for operating the first mentioned action.

3. In a fuel feed tank provided with a vacuum chamber and a duct communicating with said chamber for providing a suction therein, the combination of a plurality of levers in the said chamber, said levers forming two snap actions, a valve member connected with one of said actions for controlling the passage of air through said suction duct, a Heat in the chamber and connected with the other of said actions for controlling the operation of said action, and spring means for operating said actions, said actions being inter-connected with the valve operating action depending for its operation on the float controlled action.

4. In a fuel feed tank, the combination of a snap action comprising a pivoted lever and spring for moving the lever in either of two directions away from a dead center line, a slowly moving member and mechanism interposed between the slowly moving member and snap action and operated by the member for rapidly moving the snap action toward and beyond the dead center line.

5. In a fuel feed tank the combination of a snap action, comprising a pivoted lever and spring for moving the lever in either of two directions away from a dead center line, valve mechanism operated by the said snap action, a float, and means interposed between the float and snap action for rapidly moving the snap action toward and beyond the dead center line.

6. In a fuel feed tank the combination of a snap action, comprising a pivoted lever and spring for moving the lever in either of two directions away from a dead center line, valve mechanism operated by the said snap action, a float and a second. snap action interposed between the float and the first mentioned snap action for rapidly moving the first snap action toward and beyond the dead center line.

7. A snap action for fuel feed tanks, comprising a support, a lever having one end thereof pivoted to said support, a float attached to the other end of said lever, a second lever having one end thereof pivoted to the first lever intermediate its ends, a third lever having one endl pivoted to the other end of said second lever, valve mechanism connected with the other end of the third lever, spring means connected with the third lever tending Vto collapse the second and third levers, and stops limiting the movement of the connected ends of the second and third levers.

8. A fuel feed tank comprising a casing having a vacuum chamber and suction port communicating therewith, a valve for controlling said port and snap action mechanism for operating said valve, said mechanism comprising a lever pivoted to the casing, a ioat attached to the free end of the lever for operating said lever, a second lever having one of its ends pivoted to the first lever, a third lever pivoted to the other end of the second lever, the third lever being connected with said valve for the purpose of operatin the latter,l a spring acting between the t ird lever and the casing, tending to collapse the second and third levers, and stops for limiting movement of the second and third levers.

9. A snap action device for fuel feed tanks comprising three pivotally connected levers forming two snap actions, one depending for its operation on the other, a iioat for operating one ofthe actions, and valve operating means controlled by the other of said actions.

l0. A snap action device for fuel feed tanks comprising a slowly moving member, a snap action actuated by said member, a second snap action actuated by the first action and a valve member operated by the second action, the said second action including spring means exerting a substantially constant stress on the valve member during the movement of the first action to its actuated position, and then exerting a substantially constant stress on the valve member in the opposite direction during the movement of the first action to its reactuated position.

In witness whereof I hereunto subscribe my name this 22d day of October, 1919.

CLIFFORD C. BRADBURY.V

WVitnesses:

MARY A. COOK, ANDREW WIN'rnnconN. 

